import React, { useState } from 'react'
import Son from './components/Son'

export default function App() {
  let [count, setCount] = useState(9)
  return (
    <div>
      <button onClick={()=> setCount(count + 1)}>count ++</button>

      {count % 2=== 0 &&<Son></Son>}
    </div>
  )
}
